Are they covered with hair?
yes
What is the integument ?
- sweat, scent, sebaceous and mammary glands
How many occipital condyles do they have?
- 2
They have a secondary palate with what kind of bones?
- turbinate bones ( spongy nasal passages)
What are the 3 middle ear bones or ossicles?
- Malleus
- Incus
- Stapes
What kind of dentition do they have?
- diphyodont
L> two sets of teeth!
L> deciduous (milk teeth)
L> Permanent (adult teeth)
How many cervical vertebrae ?
- 7
What is the name of the single bone in the jaw?
- dentary
What are pinnae?
- fleshy external ears
They have ___ eyelids
moveable
They possess a __ aortic arch and ____ RBC
- left
- nonnucleated
They have a ___ developed cerebral cortex
highly
How many pairs of cranial nerves?
- 12
What type(s) of thermoregulation do they can possess ?
- endothermic (generates heat to maintain its body temperature typically above its external surroundings aka warm blooded)
- homeothermic ( stable internal body temp regardless of external influences)
Explain the integument of mammals!
- epidermis and dermis and skin is thicker than what is seen in most other verts
L> Hair, vibrasse (whiskers), horns (cows and sheep), antlers (deer) and glands
What are the four types of teeth?
- Incisors, canines, premolars and molars
-
What type of feeding classifications can they possess?
- herbivorous, insectivorous, carnivorous, and omnivorous all reflected by length of intestinal tract.
Herbivores can be further broken down into what two classifications?
- ruminants
- nonruminants ( horses, elephants, rodents)
What are Ruminants?
- four chambered stomach
- found in cattle, bison, antelopes , sheep and deer
- food passes into rumen and forms into small balls called cud
- it then passes into other chambers to be broken down by microorganisms
After the cud is broken down into pulp in the rumen it passes to where? (3)
- reticulum
- omasum where water, soluble food and microbial products are absorbed
- abomasum (true stomach acid) and small intestine where normal digestion takes place
Reproductive Patterns:
- Monotremes
- egg laying or oviparous
- embryos develop in uterus for 10-12 days
- nourished by yolk and secretions from mother
- thin shell formed prior to egg being laid
- hatch in 12 days
- young feed on milk secreted from mammary glands
Reproductive Patterns: - Marsupials L> what kind of organisms? L> placenta yay or nay? L> embryo run through! L> What's diapause?
- pouched, viviparous animals (metatheria- all living animals with abdominal pouches)
- primitive type of placental connect called choriovitelline (yolk sac)
- embryos do not implant in uterus but produce shallow depression and absorb nutrients
- have embryonic diapause ( period of arrest in development for about 235 days)
Reproductive Patterns:
- Eutherians aka?
- placental mammals
- prolonged gestation compared to other mammals
- nourished initially by the Choriovitelline placenta and later by chorioallantoic type of placenta
- prolonged lactation
What type of skull do they have?
synapsid aka one temporal opening
What was the name of the earliest synapsids? The only group of them to survive the Paleozoic era.
- Pelycosaurs
- Therapsids (early pelycosaurs carnivores)
Cynodont?
therapsids that survived the Mesozoic era , increased jaw musculature permitting a stronger bite , heterodont teeth
Heterodont teeth?
- better food processing
- diverse foods
- more than one type of tooth!
Diaphragm?
- only animals that have this
- contracts and relaxes during inhalation and exhalation to accommodates and expel air from the body
What does deciduous mean?
falling of or shed at a specific season or stage of growth (antlers, teeth etc)
Two kinds of hair?
Pelage(fur coat)
- Underhair: dense and soft, insulation
- Guard hair: coarse and longer, for protection against wear and to provide colouration
Velvet skin?
- antlers develop beneath this…..they are shed by rubbing against trees and than the antlers grow through during mating season
True horns?
- sheep and cattle (Bovidae)
- hollow sheaths embracing a core of bone from the skill, they do not shed, grow continuously and in both sexes!
Insectivorous mammals?
- eat insects as well as small invertebrates
herbivorous mammals can be divided into two categories! what are they ?
- Browsers and Grazers…hoofed animals
2. Gnawers: rodents and rabbits and hairs
What are the different types of glands (6)
- Sweat glands
- Eccrine glands
- Apocrine glands
- Scent glands
- Sebaceous glands
- Mammary glands
Sweat glands?
- found all over body
- tubular
- two kinds! Eccrine and Apocrine
Eccrine Glands? (sweat gland type)
- secrete watery fluid, if evaporated draws heat away from skin and cools it.
Apocrine glands? (sweat gland type)
- larger
- open into hair follicle
- milky fluids, whitish or yellow in colour dry on skin to form film
- regulates reproductive behaviour not heat
Scent glands?
- used for communication of the same species
- marking territory
- emit strong scents during mating seasons for attracting opposite sex
Sebaceous glands?
- hair follicle association
- dressing to keep skin and hair pliable and glossy
- polite fat = sebum
Mammary glands?
- female mammals
- rudimentary form in males
- forms a milk line
Homodont?
dentition of first synapsids \
- all the same teeth
Incisors are for?
- snipping or biting
Canines are for ?
- piercing
Premolars are for?
- shearing, slicing, crushing or grinding
Molars are for?
shearing, slicing, crushing or grinding
Cecum is for?
fermentation occurs here
- side pocket off of colon
Coprophagy?
-when an organism eats their fecal pellets giving the food a second pass through the gut to extract additional nutrients.
(rodents and rabbits do this)
Estrous?
- being in a state of heat
- when females copulate with males
- only time!
Monestrous?
-single estrous cycle during their breeding season
Polyestrous?
- recurrence of estrous during breeding season
Humans and old world monkeys do not go by estrous but by?
- menstruation, endometrium of uterus collapses and is discharged with some blood through the uterus.